1. Field of the Invention
The present invention relates to a storage apparatus and a method of reproducing information of the storage apparatus, and more particularly, to a storage apparatus and a method of reproducing information of the storage apparatus, in which information recorded in a ferroelectric recording medium is read using an electric field sensor.
2. Description of the Related Art
A Hard Disk Drive (HDD), which is a primary storage device of a computer, operates by spinning a data-recording medium and suspending a read/write head over the data-recording medium in order to read and write data. A conventional HDD normally uses a magnetic field to create a plurality of magnetic domains magnetized in a first direction on the magnetic recording medium or in a second direction opposite to the first direction. The magnetic domains magnetized in the first and second directions correspond to data ‘0’ and data ‘1’, respectively.
HDDs employing this magnetic writing method have undergone tremendous increases in terms of their writing densities over the last few decades. Thus, horizontal magnetic writing on HDDs can produce approximately 100 Gb/in2 in terms of recording density, and vertical magnetic writing on HDDs can produce approximately 500 Gb/in2 in terms of recording density. However, since it is difficult for the magnetic read/write head to form a strong localized magnetic field, the increase in recording density is limited.
Recently, research has been conducted on a ferroelectric medium (on which data is written using electric fields) and a corresponding read/write head (hereinafter referred to as electric field read/write head). An electric field writing method uses an electric field to form electric domains polarized in a first direction or in a second direction opposite to the first direction on a ferroelectric surface. Electric domains polarized in the first and second directions correspond to data ‘0’ and data ‘1’, respectively. According to the polarization direction of an electric domain, the resistance of the electric field read/write head above that domain changes, so that an amount of a current flowing between a source electrode and a drain electrode of the electric field read/write head may change. By detecting the change of the current amount, the data written in the electric domain can be discerned. According to electric field reading/writing, a high recording density of 1 Tb/in2 or more can be achieved.
The electric field read/write head applies an electric field leading to polarization of a recording medium during recording, and detects the variation of the electric field due to a polarization voltage of an electric domain of the recording medium during reproduction. The electric field read/write head functions as an electric field sensor having a channel structure of an electric field effect transistor during reproduction. To realize a more efficient and large-scale storage apparatus, the sensitivity of the electric field sensor should be improved.